A conventional packing sheet or cloth may be formed with a plurality of cells filled with air in each cell on a substrate film or sheet material. Such a cellular packing sheet may be used for packing articles in the sheet to prevent damage or breakage of the articles to be packed. However, if such a packing sheet with air cells formed on the sheet is used for cushioning device such as for serving as an insole used in a footwear or for cushioning a user's body for leaning, seating or wearing purpose, the air-filled cells may be easily broken to lose their cushioning effect. Besides, since the density of air is smaller than liquid and solid, the transformation of the air cell is fast and big when pressed. Therefore the air sheet is very soft and elastic, which may cause user feel uncomfortable when sitting or lying on it for a long time.
If a substrate sheet is formed with a plurality of protrusions on the sheet such as by integral molding of plastic processing, the protrusions may still have some hardness or rigidity to possibly stick a user to cause his or her pain when wearing, seating or leaning on such a sheet with protrusions formed thereon.
Another conventional design is to provide a cushioning device including a plurality of liquid cells encapsulated in a flexible substrate sheet wherein each liquid cell is filled with water therein and the cells are juxtapositionally disposed on the sheet so that a cellular sheet may serve as a cushioning device for a user's seating, leaning or wearing for comfortable and other cushioning purposes. When the force applied to the sheet with liquid cells is comparatively slow and equally like sitting or lying on the sheet, the sheet can provide a comfortable support. However when the force applied on the sheet is sudden and concentrated like running or jumping on insoles made of the sheet, the sheet cannot absorb the impact force immediately and the user will feel that the insoles are too hard.
Therefore a cushioning means is needed, which can make users not only feel comfortable when using the cushioning means in different situations but also can effectively absorb the force applied on the means.